| Buzzi Unicem USA - Festus, Missouri |
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Plant expansion presented three major challenges: extreme space limitations, design to severe seismic parameters, and tie-in to the existing production line without disrupting ongoing operations. Located within the central Mississippi River valley, the Selma facility sits on one of the most significant geologic fault lines in the United States - complicating the structural engineering of support foundations and production process structures. Additionally, because the plant quarry and existing kilns border the new process facilities on all four sides, design-construction sequencing proved critical. BFEI's scope of work addressed all main production areas - raw grinding, pyroprocessing, cement grinding, and cement shipping and distribution. Additionally, BFEI was charged with designing the plant's central control room. To permit the seamless integration of support systems, BFEI drew upon its in-house engineering staff - architectural, civil, structural, mechanical, piping, power and electrical system experts. Their engineering challenges were many. Coordinate and sequence work around an 18-month construction schedule. Design foundations to meet extremely high seismic parameters, as well as support the weight of massive parts, vibrating during operation. Design equipment support structures using the largest steel available in the world. Minimize the field labor required to deliver structural steel parts - too large for fabrication in the United States. And, seamlessly connect and integrate plant processing systems with several existing plant departments, insuring tie-ins with no disruptions but done within the planned shutdown periods. BFEI chose a design approach based on designing all plant areas simultaneously. Design for constructability and construction safety were paramount considerations. Scheduled to go online in early 2009, the Selma plant features an innovative vertical design and is equipped with some of the most advanced processing equipment in the industry. It includes a 400 foot, two-string, five-stage multistage combustion KHD Humboldt Wedag preheater tower as well as a KHD two-pier rotary kiln, and two 7,000 HP Loesche America vertical 6-roller grinding mills - one for raw meal, the other for clinker. In accordance with industry trends, the duplicate grinding systems boast common parts, including motors and gear boxes. A single emissions point collects production gases for operational simplicity and reduced maintenance. |
Faced with a compressed design schedule and equipment specifications testing industry limits, successfully expanding Buzzi's Selma facility required skilled engineering and expert logistics coordination. In operation for more than 40 years, the plant was in need of new raw materials receiving, storage and handling, raw grinding, clinker production, and finish grinding systems to boost clinker production capacity from 1.4 million to 2.75 million stpy. The processing equipment specified included some of the largest pieces of equipment and resulting structures in the industry worldwide.